Struct ReturnValue

pub struct ReturnValue {
    pub kind: ReturnKind,
    pub label_ops: Vec<LabelSetOpTuple>,
}

A predicted return value from an expression

Fields

kind: ReturnKind

label_ops: Vec<LabelSetOpTuple>

A stack of operations applied to original source labels

Implementations

impl ReturnValue

pub fn unknown<S>(message: S, expression: Expression) -> Self

where S: Into<String>,

pub fn label_op(&mut self, op: LabelSetOpTuple) -> &mut Self

pub fn passthrough(&self, input_labels: &[&str]) -> HashSet<String>

Given a number of input label keys, returns a set of labels expected to be present on all returned time series

Note that more labels may be returned than were provided in the input set; expressions that explicitly select for or group on labels will

pub fn drops(&self, label: &str) -> Option<&LabelSetOpTuple>

Determines the operation (plus expression and span) that caused the given label to be dropped. If the label is never dropped, returns None.

This also accounts for expressions that drop a label and re-add it later, for instance with an aggregation clause.

Trait Implementations

impl Clone for ReturnValue

fn clone(&self) -> ReturnValue

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ReturnValue

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for ReturnValue

fn eq(&self, other: &ReturnValue) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ReturnValue